Embolic protection filters are frequently utilized in combination with therapeutic devices such as revascularization catheters and stents to collect embolic debris dislodged into a patient's vasculature. In a common application such as percutaneous transluminal angioplasty (PTA) or percutaneous transluminal coronary angioplasty (PTCA), an embolic protection filter is advanced along a guidewire to a location distal a lesion or other stenosis within a vessel. Once in place, an angioplasty catheter is then advanced along the guidewire to the site of the lesion to perform the procedure. A dilatation device such as an angioplasty balloon or extraction laser is then engaged, dislodging the embolic debris from the vessel wall. The dislodged embolic debris then enters the bloodstream, and flows downstream towards the distal vasculature where it is collected and stored by the embolic protection filter.
In a typical embolic protection filter, a filter membrane is attached to a filter frame or other support means to support the filter membrane within the patient's vessel.
The filter membrane may comprise a single membrane having several openings or pores adapted to collect and store embolic debris contained within the blood while permitting the flow of blood through the embolic protection filter. Depending on the amount of embolic debris dislodged during the procedure, the openings or pores may become partially or fully occluded, causing the flow of blood within the vessel to diminish.
When this occurs, a replacement filter may need to be advanced to the site in order to replace the occluded filter. In some cases, the guidewire used to transport the device may require removal from the patient's vessel prior to insertion of the replacement filter.